In a core network of a mobile communication system, in order to provide various services to various kind of terminals (mobile stations), it is necessary that all of the nodes in the core network are provided with functions required for each service. In large-scale mobile communication network and the like, many nodes are arranged in the core network. A terminal, on every location registration, is connected in a distributed manner to nodes in the core network.
Thus, all the nodes in the core network need to have necessary functions for each service (service providing functions). When even a part of the nodes in the core network do not have the necessary service providing functions for each service, service continuity for a terminal cannot be ensured.
For example, Patent Literature 1 discloses an arrangement for optimizing a packet forwarding path based on a type of a service utilized by a mobile station, wherein, when the mobile station utilizes a service from an external network, a constraint is given to a packet forwarding path so that packet flow through a specific packet forwarding apparatus based on the external network. When the mobile station utilized a service provided by a mobile communication network, no constraint is given to a packet forwarding path.    [Patent Literature 1]    Japanese Patent Kokai Publication No. 2003-338832A